Landing gear for airplanes



Oct. 31, 1933. F. B. BELL LANDING GEAR FOR AIRPLANES 2 Sheets-Sheet 1 Filed May 22, 1 929 Oct. 31, 1933. F. B. BELL 1,933,361

LANDING GEAR FOR AIRPLANES Filed May 2. 2 2 Sheets-Sheet 2 fi f@ A Patented Oct'.31,-1933 p 1 Q UNlTlID. STATES, PATENT OFFICE LANDING GEAR FOR- AIRPLANES Frank B. Bell, Pittsburgh, Pa., assignor to Edgewater Steel Company, Pittsburgh, Pa., a corporation of Pennsylvania 7 Application May 22, 1929. Serial No. 365,045

r 5 .Claims. (Cl. 267--34) This invention relates in general to airplane mounted upon a landing gear consisting prinlanding gears, and has more particular reference cipally of wheels 13, rigid connecting struts 14,

; toairplane landing gears wherein the cushioning and elastic orshock absorbing struts 15. The i of impact and travel over the ground in taxiing showing in Fig. 1 is schematic. and thisfigure is b is absorbed and cushioned by elastic and shock provided chiefly to show generally. the location of 6 absorbing struts .arrangedibetween the wheels the elastic or shock absorbing struts with re-. and the airplane body. spect to other associated parts. The struts 15 are,

A principal object of the present invention is of course, pivotedboth to the wheel axle and to the provision of an airplane landing gear having the airplane body, and the struts 14 to the airshock absorbingor. elastic struts of novel and implane body. 55 proved construction and adapted to effectively The struts 15 are alike in construction and a absorb and cushion the shock of impactupon description of one will satisfy. Each strut 15 landing, and to absorb and cushion also the comprises extensible or telescoping members, shocks and jars of. taxiing over rough ground each of which is or may be made up of a number after landing and as anincidentto takingoif in of parts. Reference characterclfi indicates an flying. 1 I I outer tube, and referencecharacter 17 an inner Another important object of the invention is tube, these tubes being arranged in telescoping the provision of an airplane landing gear having relation. Thetube 17 is provided with a cap or elastic or shock absorbing struts constructed and closure 18 having a perforated web or extension arranged to minimize or eliminate bouncing of 19. adapted for pivotal connection to the airplane the airplane in taking off and landing, and conbody. The outer telescoping member or tube 16 structed and arranged also to minimize tendency is provided with a like cap or head 21 having a of the airplane body to swerve or rock in turning perforated web or extension 22 for similar consharply in taxiing. V s nection to the running gear or wheelaxle of the Another important object of the invention is airplane. The outer member or tube 16 is of di- 80 the provision of an improved shock absorbing ameter substantially larger than the diameter of strut for an airplane landing gear which, while the inner tube or member 17 and is provided with efiectively cushioning the airplane in landing and a reducing collar or sleeve 23 slidably engaging also in taxiing over rough ground. will consist the outer surface of the inner tube or member 17, of a minimum number of sturdy parts of simple packing 24 being provided if desired to make a construction apd'unlikely to require frequent reliquid-tight fit between the telescoping members pair, replacement or attention in service. or tubes.

Numerous other objects and advantages of the The collar or sleeve 23 is preferably provided invention will be apparent as it is better underwith external threads 25 arranged below an outstood from the following description which, when wardly extending shoulder 26. The tube 16 has 90 taken in connection with the accompanying companion threads at its upper open end engagdrawings, discloses a preferred embodiment ing the threads 25 and permitting its secure conthereof. nection to the sleeve when the end of the tube 16 Referring to the drawings: is screwed against the shoulder 26 as may be ob- Figure 1 is a front elevation of an airplane served in Figs.3 and 4.

provided with landing gear struts embodying my A plunger 2'7 is arranged within the tube 16 and present invention. is provided with a central restricted opening or Fig. 2 is an enlarged side elevation of one of orifice 28. The plunger is preferably provided the landing gear struts shown in Fig. 1, parts with a cup washer 29, which is held in place by a being shown in section; plunger cap 31 screwed on the end of the plunger Figs. 3 and 4 are fragmentary views further and confining the inner end of the cup washer enlarged and broken away, showing features of against the plunger head internal construction; The inner tube 1'7 extends well down within the Fig. 5 is a section taken substantially on the tube 16 and well into the plunger 27. A cross bolt line 55 of Fig. 3; and 33 is arranged through the plunger and through Fig. 6 is a section taken substantially on the slots 34 provided at diametrically opposite walls line 6-6 of Fig. 3. of the tube 17. 5

Referring first more particularly to Fig. 1', ref- A spring 36 is interposed between the plunger erence character 11 indicates generally the airand a shoulder 35 provided on the inner tube or plane body. This body has wings 12, and is member 17 and extending outwardly into closely adjacent relation with the inner surface of the outer tube or member 16. The spring 36 is or may be of any usual or preferred form, one of coil type being shown on the drawings.

A bearing collar 41 is or may be provided between the shoulder 35 and the upper end of the spring. When the parts are assembled, compression may, if desired, be given the spring 36, this compression being maintained by the bolt 33 and the engagement of it with the lower ends of the slots 34. A quantity of oil or other liquid is provided within the telescoping tube members 16 and 17 and through an opening in the cap 18 and tube 17, which opening is shown on the drawings as closed by a set screw or a plug 42. Reference character 40 indicates an oil drain opening at the bottom of the cap 21, a plug 44 being provided to close this drain.

Referring to Fig. 3, the arrangement of the parts of the shock absorbing struts in fully extended relation may be observed. This is their arrangement when the airplane is flying and the landing gear is suspended from the airplane body. At this time, the oil or liquid has flowed downwardly through the orifice 28 to fill the chamber 43 therebelow. Upon landing, the initial impact or shock is transmitted through the spring 36 to the plunger, and the oil or liquid is forced rapidly through the opening or orifice 28, the spring 36 cushioning the jar of impact and cushioning also the transmission of force to the plunger and liquid.

Fig. 4 illustrates the relative positions of the parts when the airplane is resting upon the ground and when it is taxiing over the ground after the oil or liquid has flowed through the orifice 28 as a result of the landing. In taxiing, the shocks resulting from running across uneven ground is felt by and absorbed in the spring 36, as will be readily understood. It will be manifest that the resistance to shock is much greater upon the landing of the airplane, since at that time both the liquid orifice cushioning and the spring 36 are acting together.

It is thought that the invention and many of its attendant advantages will be understood from the foregoing description,and itwill be apparent that various changes may be made in the form, construction and arrangement of the parts without departing from the spirit and scope of the invention or sacrificing all of its material advantages, the form hereinbefore described being merely a preferred embodiment thereof.

I claim:

1. In an airplane landing gear, a shock absorbing strut comprising members relatively arranged to be held in extended relation and to contain a quantity of liquid, a said member having an orifice. through which said liquid must move upon compression of the strut, and a spring transferring the compressive force to said liquid to force said liquid through said orifice upon compression of said strut.

2. In an airplane landing gear, a shock absorbing strutcomprising telescoping members, a plunger arranged within a said member and adapted to bear upon and permit passage of liquid contained in a said member, and a spring in terposed between a said member and said plunger for transferring pressure of compression to said liquid, said spring being adapted to sustain the load of the airplane and cushion its movement in taxiing.

3. In an airplane landing gear, a shock absorbing strut comprising members arrangeable in extended relation when the airplane is in the air, said members providing a chamber to contain a body of liquid between them when in extended relation and having an orifice through which said liquid must pass upon compression, and means for cushioning impact compressingsaid strut and cushioning also the compression of the liquid before passage through said orifice.

4. In an airplane landing gear, a shock absorbing strut, comprising telescoping members arrangeable in extended relation when the airplane is in the air, a liquid carried in said members, a plunger having an orifice and presenting a full lower face except for the orifice to'said liquid, and a spring transmitting the shocks of landing to said liquid through said plunger.

5. In an airplane landing gear, a shock absorbing strut, comprising a pair of telescoping sleeves having body portionsspaced apart, a plunger movable between said body portions and having an orifice for the transmission of liquid, and a spring arranged'between said bodyportions and bearing upon said plunger to transmit shock of landing through said plunger to said liquid.

' FRANK B. BELL. 

